Anastomosis is a procedure where two separate tubular or hollow organs are surgically grafted together to form a continuous fluid channel between them. Vascular anastomosis involves creating an anastomosis between blood vessels to create or restore blood flow. When a patient suffers from coronary artery disease (CAD), an occlusion or stenosis in a coronary artery restricts blood flow to the heart muscle. In order to treat CAD, the area where the occlusion occurs is bypassed to reroute blood flow by grafting a vessel in the form of a harvested artery or vein, or a prosthesis. Anastomosis is performed between a graft vessel and two target vessels in order to bypass the blocked coronary artery, circumvent the occlusion and restore adequate blood flow to the heart muscle. This treatment is known as a coronary artery bypass graft procedure (CABG).
An anastomosis may be compliant or noncompliant. A noncompliant anastomosis is one in which the anastomosis opening in the target vessel is not substantially free to expand or contract radially. A noncompliant anastomosis may be formed with a one-piece or multiple-piece anastomosis device that compresses or otherwise controls tissue in the vicinity of the anastomosis to hold the graft vessel in place relative to the target vessel. Noncompliant anastomoses have been successful, such as when utilizing anastomosis devices deployed by Cardica's PAS-Port™ anastomosis system. A compliant anastomosis is one in which the target vessel is substantially free to expand or contract circumferentially and longitudinally in proximity to the anastomosis site. A traditional sutured anastomosis is compliant, and for this reason some surgeons would prefer to utilize an anastomosis system that provides a compliant anastomosis, particularly between a graft vessel and the aorta or other source of arterial blood.